Qualitative and Quantitative Investigation of Laminar-to-Turbulent Transition in Steady and Unsteady Boundary Layers

Project Title: Qualitative and Quantitative Investigation of Laminar-to-Turbulent Transition in Steady and Unsteady Boundary Layers
Project Type: TÜBİTAK-ARDEB 1001
Project Coordinator: Prof. Dr. Veysel Şadan Özgür Kırca

In this research project, major purpose is the qualitative and quantitative investigation of laminar-to-turbulent transition in the case of steady non-uniform (spatially developing) boundary layers, as well as unsteady (temporally developing) boundary layers. In the scope of the project, typical geometric, kinematic and dynamic conditions in the boundary layer during laminar-to-turbulent transition, coherent structures related with these conditions, the spatial and temporal variation of instantaneous flow parameters (velocity and pressure) associated with emergence and development of turbulence in the boundary layer are investigated. Both physical modeling and numerical modeling methods are employed in the project. In the context of physical modeling, experiment are conducted in the lab by use of Particle Image Velocimetry (PIV) and flow visualization via laser sheet to investigate laminar-to-turbulent transition in two different types of boundary layers; non-uniform steady flow, and unsteady boundary layer under progressive waves.The second method to be applied in the project is the Direct Numerical Simulation (DNS). The DNS technique enables modeling of turbulent or transitional flows without the necessity of any empirical approach or simplification. To this end, ITU-UHeM supercomputers are employed for numerical modeling. When completed, the results of project will help to better understand the laminar-to-turbulent transition in developing boundary layers.